Journal article
Anteroventral Third Ventricle Lesions Abolish Lumbar Sympathetic Responses to Insulin
Hypertension (Dallas, Tex. 1979), Vol.23(6, Part 2), pp.1059-1062
06/1994
DOI: 10.1161/01.HYP.23.6.1059
PMID: 8206594
Abstract
Insulin has been shown to increase sympathetic nerve activity. Because evidence shows that insulin acts within the central nervous system, we hypothesized that lesions of the anteroventral third ventricle region, an area rich in insulin receptors, would abolish sympathetic responses to hyperinsulinemia. We measured mean arterial pressure and lumbar sympathetic nerve activity in fasted, anesthetized sham-lesioned (n=8) and lesioned (n=8) rats before and after intravenous insulin infusion at 0.13 U/h during euglycemic clamp. Additional sham-lesioned (n=10) and lesioned (n=5) rats received vehicle infusion. Insulininfused sham-lesioned rats had substantially greater increases in lumbar sympathetic nerve activity (+83±18%) than vehicle-infused sham-lesioned rats (+27±4%). Most importantly, insulin-infused lesioned rats had increases in sympathetic activity (+32±11%) that were no greater than lesioned rats receiving vehicle (+23±16%). Blood pressure was not altered by insulin or vehicle. To test the possibility that lesions of the anteroventral third ventricle region nonspecifically suppress sympathetic excitatory responses, we evaluated reflex increases in lumbar sympathetic activity to nitroglycerin in sham-lesioned (n=5) and lesioned (n=8) rats. Rats with lesions and sham lesions showed comparable increases in lumbar nerve activity during nitroglycerin-induced hypotension. In summary, increases in sympathetic nerve activity to intravenous insulin infusion are abolished by anteroventral third ventricle lesions. These data indicate that the integrity of this brain region is necessary for activation of lumbar sympathetic nerve activity by systemic administration of insulin.
Details
- Title: Subtitle
- Anteroventral Third Ventricle Lesions Abolish Lumbar Sympathetic Responses to Insulin
- Creators
- Martin Muntzel - Departments of Psychology, Pharmacology, and Internal Medicine and the Cardiovascular Center, College of Medicine, University of Iowa, and the Veterans Affairs Medical Center, Iowa CityTerry BeltzAllyn MarkAlan Johnson
- Resource Type
- Journal article
- Publication Details
- Hypertension (Dallas, Tex. 1979), Vol.23(6, Part 2), pp.1059-1062
- Publisher
- American Heart Association, Inc
- DOI
- 10.1161/01.HYP.23.6.1059
- PMID
- 8206594
- ISSN
- 0194-911X
- eISSN
- 1524-4563
- Language
- English
- Date published
- 06/1994
- Academic Unit
- Psychological and Brain Sciences; Neuroscience and Pharmacology; Health and Human Physiology; Internal Medicine
- Record Identifier
- 9984213425002771
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